Corneal disorders are the leading cause of global blindness and affect 1.5 million Americans each year. Tissue-targeted and localized gene therapy for the cornea offers promise to cure, reduce and/or prevent corneal blindness caused by trauma, injury, infection or inherited dystrophies. The long-range goal of our research is to define clinically applicable, simple, minimally invasive targeted gene-based therapies for corneal blindness. Recently, we demonstrated that targeted adeno-associated virus (AAV)-decorin gene therapy efficiently inhibits corneal fibrosis and neovascularization in vivo in rabbits. It did not show any short-term toxicity. Our central hypothesis is that decorin is a master regulator of corneal healing and, acting as a signaling molecule, it interacts with many cytokines and/or their receptors and prevents excessive healing and disease in the cornea. We found decorin in the cornea interacts with transforming growth factor ? (TGF??), epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF). Our RNA knockdown studies revealed that TGF?? mediates corneal fibrosis via Smad signaling, and Smad7 is an attractive target to block TGF?? pathologic activity. The goals of this project are: i) test whether efficacious AAV-decorin gene therapy has any long-term toxicity for the cornea, ii) collect cornea-specific data and an understanding of the molecular mechanism of decorin functions in the cornea, and iii) identify additional gene-based therapy for corneal blindness. One treatment does not work for all patients due to variations in medical conditions, susceptibility to medication, tolerance level etc. The Specific Aims are: (1) Test the hypothesis that targeted decorin delivery into rabbit keratocytes in vivo does not alter fibril structure or characteristic organization in the stroma, modulates keratocyte differentiation, migration and proliferation, and regulates corneal healing. (2) Test the hypothesis that targeted AAV-Smad7 gene therapy is a novel approach to disrupt TGF? signaling and prevent myofibroblast formation and fibrosis in the cornea in vivo. (3) Test the hypothesis that tissue-selective AAV-PEDF gene therapy delivered into rabbit keratocytes in vivo inhibits corneal neovascularization in rabbits without significant adverse effects. These aims will be tested using well-defined rabbit disease models, recently defined targeted AAV therapy approaches, established protocols and techniques, including slit-lamp, stereomicroscope and optical coherence tomography, immunohistochemistry, immunoblotting, quantitative PCR, southern blot, transmission electron and confocal microscopy, etc. The proposed experiments will provide important answers to how AAV- mediated decorin, Smad7 and PEDF gene therapy may be used, alone and in combination, to restore vision or prevent blindness from corneal scarring or neovascularization. They also will provide answers to many fundamental questions about corneal healing, and the role of keratocyte and cytokines in corneal disorders and diseases. PUBLIC HEALTH RELEVANCE: Corneal scarring and neovascularization following trauma, injury or infection cause blindness. Targeted gene therapy delivered to the cornea with a simple topical technique offers promise to cure, treat and/or prevent vision loss by modulating excessive healing mechanisms that cause these blinding corneal disorders.